Exelixis initiates phase 3 trial of Cabozantinib/Atezolizumab combo in prostate cancer

Exelixis, Inc. announced the initiation of CONTACT-02, a global phase 3 pivotal trial of cabozantinib (CABOMETYX) in combination with atezolizumab (TECENTRIQ) in patients with metastatic castration-resistant prostate cancer (CRPC) who have been previously treated with one novel hormonal therapy.

CONTACT-02 is part of a clinical trial collaboration between Exelixis and Roche that includes two additional phase 3 pivotal trials – CONTACT-01 in patients with metastatic non-small cell lung cancer (NSCLC) who have been previously treated with an immune checkpoint inhibitor and platinum-containing chemotherapy, which was initiated in June, and the planned CONTACT-03 trial in patients with metastatic renal cell carcinoma (RCC) who previously received an immune checkpoint inhibitor.

“As many patients with advanced, castration-resistant prostate cancer who have progressed on a novel hormonal therapy wish to avoid or delay chemotherapy, more treatment options are needed,” said Gisela Schwab, M.D., President, Product Development and Medical Affairs and Chief Medical Officer, Exelixis. “We are encouraged by the positive early stage results for the combination of cabozantinib and atezolizumab seen for prostate cancer patients in cohort 6 of the COSMIC-021 trial, and we are pleased to begin this pivotal trial that will further evaluate how the combination may improve outcomes for these patients as part of our ongoing partnership with Roche.”

CONTACT-02 is a global, multicenter, randomized, phase 3, open-label study that plans to enroll approximately 580 patients at 250 sites. Patients will be randomized 1:1 to the experimental arm of cabozantinib in combination with atezolizumab and the control arm of a second novel hormonal therapy (either abiraterone and prednisone or enzalutamide). The co-primary endpoints of the trial are progression-free survival and overall survival. Additional endpoints include objective response rate, prostate-specific antigen response rate and duration of response. The trial is sponsored by Exelixis and co-funded by Roche, Ipsen and Takeda Pharmaceutical Company Limited.

The design of CONTACT-02 was informed by results from the ongoing COSMIC-021 trial — a phase 1b study of cabozantinib and atezolizumab in multiple advanced solid tumors including NSCLC, CRPC and RCC. Initial results from cohort 6 were presented at the 2020 American Society of Clinical Oncology’s Genitourinary Cancers Symposium. The interim analysis was updated with additional biomarker results and presented at the 2020 American Society of Clinical Oncology Virtual Scientific Program.